Electric motor



Oct. 17, 1950 J. A. SCHWARZ 2,525,836

ELECTRIC MOTOR Filed Nov 4, 1947 2 Sheets-Sheet 1 Oct. 17, 1950 J. A. SCHWARZ ELECTRIC MOTOR 2 Sheets-Sheet 2 Filed Nov. 4, 1947 m? WM Patented Oct. 17, 1950 ELECTRIC MOTOR Joseph A. Schwarz, Chicago, 111., assignor to Birtman Electric Company, a corporation of Illinois Application November 4, 1947, Serial No. 783,940

6 Claims. (01. 172-36) This invention relates to an electric motor, and relates particularly to a lightweight electric motor of simple construction.

The ordinary electric motor comprises an armature, field laminations, field coils, a commutator, brushes a casing and other elements. In some cases it is very desirable to have the motor as light in weight as possible for any given horsepower rating. The ordinary motor, however, is relatively heavy and of considerable bulk because of the large number of parts needed and the fastening means used in arranging these parts in their assembled relationship. I have invented a motor that is relatively lightweight yet of strong and sturdy construction. The various parts of the motor are quite simple in construction and the means employed for holding the parts together are relatively simple, and in many cases, one part is used to perform more than one function.

The casing of the new motor is formed of a pair of members adapted to be held in abutting relationship with these members held in such relationship by means of brackets and flanges on the inner surfaces of the casing members. The flanges are preferably cut from one of the easing members, while the brackets are used not only to hold the casing members together, but also to serve as mounting members for the brush holders. The fastening means that xtends between the flanges and the brackets is also preferably used to support the field laminations. With such an arrangement the motor is quite simple in construction, light in weight and is relatively inexpensive to build.

The invention will be described as related to the embodiment shown in the accompanying drawings. Of the drawings, Fig. l is a longitudinal vertical section through the motor; Fig. 2 is an end elevation of the motor looking from the left-hand end of Fig. l and with portions thereof in section; and Fig. 3 is a section taken along line 33 of Fig. 1.

The electric motor shown in the accompanying drawings comprises a front casing member ID and a rear casing member II adapted to be held with their edges in abutting relationship. Each casing member is substantially one-half of the total casing and when in disassembled relationship are of substantially cup shape. The front casing member I is provided with a pair of inwardly extending flanges Na and I017 located substantially diametrically opposite each other and extend toward each other. These flanges are cut from the casing member I0 so as to leave openings I00 and I M.

The rear casing member II is provided with a pair of brackets I2 and I3 attached to the inner surfaces thereof by any means desired. The bracket I2 is provided with an inwardly extending portion I2a, while the other bracket I3 is provided with a similar portion I3a. These bracket portions I 2a and I30. extend toward each other and are substantially coplanar. One bracket portion I2a is adapted to be arranged opposite a flange Illa, while the other bracket portion l3a is also adapted to be arranged opposite a flange Illb. These bracket portions and flanges will occupy this arrangement when the casing portions l0 and II have their open edges in abutting relationship as shown in Fig. 1. The bracket portions I2a and I3a are provided with threaded openings with each opening being adapted to retain a threaded bolt I4 extending between a flange and the bracket portion. Thus, one bolt I4 extends through a hole in the flange Illa and has its end retained in the threaded hole in the bracket portion [2a. The other bolt is similarly held so as to extend between flange Nb and bracket portion I3a. These bolts I4 serve to hold the casing portions l0 and II in their assembled relationship with the edges thereof abutting each other.

Arranged between the flanges Illa and Iflb and the bracket portions in and I3a are assembled field laminations I5. These field laminations are also held in place by the bolts I4 and the laminations also serve to give greaterstability to the casing members. The armature ill of the motor is located within an opening in the field lamina: tions I5 and is located between the edges of bracket portions I 2a and [3a and flanges Illa and Illb. The field coils I! are supported on the field laminations I5.

Each bracket I2 and I3 is provided with a second inwardly extended portion of which one I2b is shown. Each of these second bracket portions is adapted to be arranged opposite the commutator I8 of the armature IS. The second bracket portion I2!) is used to rotatably support a brush holder I9 for a brush 20. The second bracket portion on the other bracket I3 is similarly arranged to hold another brush holder 2| for a second brush 22. Each brush holder, which is rotatably supported on a second bracket portion, may be locked against rotation by means of a screw 23. Each of the brush holders I9 and 2| is formed with a base portion, such as [9a, and a brush holding portion I9b having an open side. This open side is normally closed by a sheet 24 of an insulating material held in place by the screw 23. The second brush holder is similarly provided with a second sheet of insulating material.

One of the brushes 20 is urged against the commutator I8 by means of a coil compression spring 26 having its upper end bearing against a cup 21 and its bottom end bearing against the outer end of the brush. The cup 21 bears against an insulating'cap 28 which is also cup shaped. This cap is held in a threaded hole in the casing member II opposite the brush holder I9. The second brush 22 is similarly provided with a spring 29, cup 30, and cap 3|.

The armature I 6 is mounted on a shaft 32 having one end extending outside the motor casing. The rear end of the shaft is held in a substantially spherical bearing 33 having its back portion pressing against a spherical projection Ila at the rear of the'rear casing member II andits front-surface held by-a plate 34 that is attached to the inner surface of the rear casing member II. The area Nb of the rear casing member that is adjacent the projection Ila is spaced from the plate 34 in order to provide space for a felt oil reservoir 35. This felt may be saturated with oil through an opening He. The bearing 33 is prevented from rotating with the shaft 32 by an inwardly projecting flange 34a on the plate 34 which engages a depression 33a in the surface of the bearing. In order to prevent oil from the bearing from traveling to the commutator I8 there is provided a substanacsaasee I tially circular plate 36 located between the bearing 33 and the commutator I8. This plate is arranged to rotate with the shaft.

The front-end of the shaft 32 is similarly held in a bearing-31 which is also provided with a felt oil reservoir fiii and a plate 39 serving to locate the reservoir and hold the bearing 37 in place. Immediately behind the bearing 31 there is located-an oil protecting plate 40 mounted on the shaft'32. Between this plate and the armature I6 there is located an air cooling fan 4| also mounted on the shaft 32. This fan serves to force air through the motor and cool the parts thereof.'

Each of the brackets I2 and I3 are provided with one or more screws 42 having their shank portions held in the bracket and their head portions located inthe casing member l I with the top of the head being substantially flush with the outer surface of the casing member. These screws serve to prevent movement of the brackets relative to the casing member II.

In the embodiment of the invention shown in the drawings there are provided a pair of spaced support brackets 43 and 44 by means of which the motor may be suspended from a base member. The rear bracket t3 is attached to the casing by means of a screw 45 that extends through a flange on the bracket, the rear casing member II, and the internal bracket I2. The front support bracket 44 may be held in place by means of a similar screw, by welding or by any other desired means.

The opening I30 that results from the formation of the flange Illa may serve as a point of access for the motor lead Wires 86. This opening may then be covered by a terminal box 4'! into which the wires 46 extend and which serves as a means for connecting the motor to a source of electric power. The other opening lob in the casing I0 may be covered by a name plate 48 or the like. In order to provide cooling air to the motor, the casing members may be provided with openings or slots in the ends thereof. The slots in the rear casing member I I are shown in Fig. 2 and are in the form of arcuate slots I Ed. The other casing member I0 may also be provided with similar slots or openings. Air will be drawn by the fan 4| through one set of openings, forced through and around the motor and exhausted out the other. set of openings 0rslot's'=.- 3 l Although the casing members I 0 and II are shown in the drawings as having two opposite sides flattened, it is, of course, obvious that this is not necessary to the invention as any shape casing maybe used.

Having described my invention as related to the embodiment shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description unless otherwise Especified, but rather be construed; broadly within its spirit and scope as 'set out in the; accompanying claims.

Iclaimz 1..I n, a motor. including an f armature having a-commutaton fieldlaminations, field coils and brushes, a casing comprising a pair of members adapted to ..be'; held abutting relationship, a bracket attached, toflone ofsaid. members on the inner surface thereof and spaced inwardly from the outer end .of said one member, a flange cut from the. otherlof said members and turned inwardly to leaveahola'abrush holder mounted on one portion of lsaidbracket, and bolt means extending between another portion of said bracket and said'flang'e' to hold the casing members in said abutting relationship.

2. In a motor including an armature having a commutator, field laminations, field coils and brushes, a casing'comprising. a pair of members adapted'to be held in abutting relationship, a bracket attached to one ofsaid members on the inner surfacethereof and having a pair of inwardly extending portions one of which is adjacent the commutator, a flange cut from the other of said members and turned inwardly to leave a hole, a brush holder mounted on said one bracket .portion,,and bolt means extending between said other bracket portion and said flange to hold the. casing members in said abutting relationship.

3. The motor of claim 2 wherein said brush holder is rotably mounted on said one bracket portion, and means are provided for locking said holder on said portion.

4. In a motor includingan armature having a commutator, field laminations, field coils and brushes, a casing comprising a pair of members adapted to be held in, abutting relationship, a bracket attachedto one of said members on the inner surface thereof and having a pair of inwardly extending portions one of which is adjacent the commutator, ,a flange cut from the other of said members and turned inwardly to leave a hole,-a;br.u sh holder rotatably mounted on said one bracket portion, means for locking the brush holder on said one bracket portion, said holder having an open :side normally: closed by an insulating memberheld in place-by said holding means, and bolt means extending between said other bracket portionandsaid flange with at least a portion of the field laminations being located between said other bracket portion and the flange whereby-the bolt means serves to hold said portionof the field laminations and to hold the casing members in said abutting relationship. 3 J.

5. In a motor including a casing, an armature and brushes, a bracket attached to the interior of the casing and having an inwardly-extending portion adjacent the armature, said bracket portion having a surface extending substantially transversely to the axis of said armature, a brush holder having a cavity in which the brush is held With said cavity having an open side, a removable insulating member normally closing said open side, and means pivotally mounting said brush holder on said surface of said inwardlyextending portion of said bracket.

6. In a motor including a casing, an armature and brushes, a bracket attached to the interior of the casing, a brush holder pivotally attached to said bracket, and means for locking said holder on said bracket, said brush holder being provided with an open side that is normally closed by an insulating member held in place by said locking means.

JOSEPH A. SCHWARZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 805,499 Stoycheff Nov. 28, 1905 2,176,118 Brinda Oct, 17, 1939 2,300,957 Miner Nov. 3, 1942 FOREIGN PATENTS Number Country Date 500,417 Great Britain Feb. 8, 1939 

